Microplastic atmospheric pollution in an urban Southern Brazil region: What can spider webs tell us?

The World Health Organization categorizes air pollution as the presence of one or more contaminants in the atmosphere such as smoke, dust, and particulate matter like microplastics, which are considered a priority pollutant. However, only a few studies have been developed on atmospheric pollution, and knowledge about MPs in the atmosphere is still limited. Spider webs have been tested and used as a passive sampling approach to study anthropogenic pollution. Despite this, studies on microplastic contamination using spiderwebs as samplers are scarce. Thus, this study uses spider webs as passive indicators to investigate air quality regarding microplastic contamination in an urbanized area. Therefore, 30 sampling points were selected, and webs of Nephilingis cruentata were collected. The spider webs were dipped in KOH 10 %. After digestion, the solution was washed and sieved through a 90 µm geological sieve. The remaining material was transferred to a Petri dish with filter paper, quantified, and identified by type and color. The chemical composition of the polymers was determined using Raman spectroscopy. 3138 microplastics were identified (2973 filaments and 165 fragments). The most frequent colors were blue and black. Raman spectroscopy revealed five types of polymers: Isotactic Polypropylene, Polyethylene Terephthalate, Polyurethane, Polyamide, and Direct Polyethylene.

Abundance, composition, and distribution of microplastics in intertidal sediment and soft tissues of four species of Bivalvia from Southeast Brazilian urban beaches.

In coastal areas, microplastics (MPs) can deposit in sediment, allowing it to be ingested by benthic organisms, like mussels, thus creating a possible transfer to humans. The aim of this study is to evaluate MPs pollution in sediment as a function of shoreline elevation in two urbanized beaches and to evaluate the abundance/frequency of MPs in 4 different species of bivalves commonly used in the human diet, such as the oyster Crassostrea brasiliana, the mussels Mytella strigata and Perna perna and the clam Tivela mactroides, and identify the polymers via µ-FTIR technique. A total of 3337 MPs were found in this study, of which 1488 were found in the sediment at the five sites analyzed, and 1849 in the bivalve tissues at the two sampling sites. MPs contamination was observed in all sediment samples and species of the pool and in each of the 10 specimens of the four species. Thus, the frequency of contamination by MPs reached 100 % for the analyzed samples. The number of filaments is higher than fragments in sediment samples and in each bivalve species. Regarding types and colors, the blue were greater than fragment-type in sediments and samples. In an effort to classify the polymers via µ-FTIR, our study was able to identify polypropylene, polyethylene and polyethylene terephthalate, besides a great number of cellulose fibers.

Spatial distribution of microplastics in the superficial sediment of a mangrove in Southeast Brazil: A comparison between fringe and basin.

The presence of microplastics (MPs) has been observed globally in every marine environment, including mangroves. However, the distribution of MPs in mangroves comparing fringe and basin forests and their ecological consequences need be better investigated. The objectives of this study were to verify the presence, distribution and types of MPs in a mangrove area in southeast Brazil. Further, we linked the presence of vegetation and urban activities with MPs presence at these sites. Eight mangrove sites in Vitória Bay were delimited and classified as fringe or basin, totaling 16 sample points. Superficial sediments were collected, then MPs classified and quantified by shapes and colors. A total of 2175 MPs were observed in the mangrove basin and fringe of sites analyzed (66.4% and 33.6%, respectively), suggesting high levels of MPs in basin sites. The color proportion of MPs found was blue (54%), transparent (21%), black (10%), red and green (6% each) and yellow and white (<1% each). Filaments accounted for 88.7% of the total, compared with 11.3% from fragments. The majority of MPs were found at the basin sites with less preserved vegetation. A positive correlation was found between the total number of MPs and the density of dead vegetation, indicating that degraded environments are more susceptible to MP accumulation. Thus, our data suggest that MPs are widely distributed and associated with lower hydrodynamism (basin region), less preserved vegetation and urban activities.

Quantitative evaluation of microplastics in colonies of Phragmatopoma caudata Krøyer in Mörch, 1863 (Polychaeta-Sabellariidae): Analysis in sandcastles and tissues and identification via Raman spectroscopy.

The detection of microplastics in all world oceans, including the most remote, has become a major concern as this will substantially increase the possibility of interactions between these particles and the marine biota. Due to their small size, microplastics can be ingested by many marine species including invertebrates, causing physical damage. This study was the first evaluation of the occurrence and abundance of microplastics in three sample types related to the species Phragmatopoma caudata, (i.e. colony wash water, tubes and digested tissue from specimens). In total, 2118 samples of microplastics were quantified, with 1516 obtained from the wash water, 447 from the fragmented tubes and 155 from the digested tissue. Three types of microplastics were chemically identified via Raman Spectroscopy as polyethylene, polypropylene and polyethylene terephthalates. Overall, this study demonstrated that microplastics are abundantly bioavailable in the studied area and are present as filament and fragment shapes.